Please make it more SEO friendly... Can we edit tag and description of all the pages/topics?
Meta description has absolutely no effect on search result position. It's useless for SEO purposes. Frankly, it should just get pulled out completely.
Also, I echo Arantor's comments on you sitting down and tagging every single topic. Not hard for a small board with minimal traffic, impossible on a medium board as you'd spend all your time trying to come up with decent tags.
Is it possible to design in such a way that we can transfer the forum from one host to other directly... I mean just few click and download a large file containing all html file and MySql and with another click it would be uploaded to any host or any thing better than this?
Not possible without making things very
complicated. Also, it wouldn't scale well at all. As it is, the built-in database-only backup feature of SMF has problems on some hosts and will not work on large forums. Additionally, as each hosting provider is slightly different, you'd have to try to accommodate a lot of variability.
If you don't allow attachments and uploaded avatars on your forum, you can get away with just a plain database backup.